Adjustable immobilizer device and method for immobilizing a patient

ABSTRACT

Systems for immobilizing a patient are disclosed. The system includes at least one preform formed from a low melting temperature thermoplastic, the preform being configured to be formed to the anatomy of the patient, at least one frame coupled to the at least one preform, and at least one support configured to support the anatomy of the patient. The system also includes at least one lock mechanism coupled to at least one of the frame and the support and configured to couple the at least one frame to the at least one support, and at least one adjuster mechanism coupled to at least one of the at least one frame and the at least one support and configured to selectively adjust a distance between the at least one frame and the at least one support while the at least one frame is coupled to the at least one support.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of, and claims thebenefit of, pending U.S. patent application Ser. No. 16/223,848 titled,“ADJUSTABLE IMMOBILIZER APPARATUS AND METHOD FOR IMMOBILIZING APATIENT,” filed on Dec. 18, 2018, which is a continuation of pendingU.S. patent application Ser. No. 14/913,760, titled “ADJUSTABLEIMMOBILIZER APPARATUS AND METHOD FOR IMMOBILIZING A PATIENT,” filed Feb.23, 2016, which is the national stage application of, and claims thebenefit of, PCT/US2015/014090, filed on Feb. 2, 2015, which claims thebenefit of U.S. Provisional Application No. 62/102,358, titled“ADJUSTABLE IMMOBILIZER DEVICE AND METHOD FOR IMMOBILIZING A PATIENT,”filed on Jan. 12, 2015, and U.S. Provisional Application No. 61/941,542,titled “ADJUSTABLE IMMOBILIZER DEVICE AND METHOD FOR IMMOBILIZING APATIENT,” filed on Feb. 19, 2014, the contents of each of theseapplications being incorporated by reference in their entirety hereinfor all purposes. This application is also a continuation applicationof, and claims the benefit of, pending U.S. patent application Ser. No.14/913,760, titled “ADJUSTABLE IMMOBILIZER APPARATUS AND METHOD FORIMMOBILIZING A PATIENT,” filed Feb. 23, 2016.

BACKGROUND OF THE INVENTION

There is a growing need for improved devices that can immobilizepatients or patient anatomies. For example, thermoplastic sheets areknown and used as patient immobilizers in radiation therapy to reduce orprevent movement of patient anatomies during therapy. Such sheets areheated to become formable, formed over a part of a patient's anatomy,and then cooled to harden, thereby immobilizing the patient or patient'sanatomy for the treatment therapy.

Patient immobilization is particularly important when performingstereotactic radiosurgery. In this procedure a high dose of radiation isdelivered to the patient over one or a small number of treatments. Ahigh degree of patient immobilization is required.

Despite developments that have been made in connection with suchdevices, there remains a need for improved patient immobilizers as wellas improved methods and processes for immobilizing patients in terms ofat least one of cost control, enhanced performance, and ease of use.

SUMMARY OF THE INVENTION

Aspects of the present invention are directed to apparatus, systems, andmethods for adjustably immobilizing a patient.

In accordance with one aspect of the present invention, a system forimmobilizing an anatomy of a patient is disclosed. The system includesat least one preform formed from a low melting temperaturethermoplastic, the preform being configured to be formed to the anatomyof the patient, at least one frame coupled to the at least one preform,and at least one support configured to support the anatomy of thepatient. The system also includes at least one lock mechanism coupled toat least one of the at least one frame and the at least one support andconfigured to couple the at least one frame to the at least one support,and at least one adjuster mechanism coupled to at least one of the atleast one frame and the at least one support and configured toselectively adjust a distance between the at least one frame and the atleast one support while the at least one frame is coupled to the atleast one support.

Further aspects of the invention include a system for immobilizing ananatomy of a patient. The system includes an immobilization elementcontoured to receive the anatomy of the patient, and a supportconfigured to support the anatomy of the patient. The system alsoincludes a lock mechanism coupled to at least one of the support and theimmobilization element and configured to affix the support with respectto the immobilization element, and an adjuster mechanism coupled to atleast one of the support and the immobilization element, the adjustermechanism being configured to selectively adjust a distance between thesupport and the immobilization element while the immobilization elementis coupled to the support.

Additional aspects of the invention are directed to an apparatus forimmobilizing an anatomy of a patient. The apparatus includes a preformformed from a low melting temperature thermoplastic, the preform beingconfigured to be formed to the anatomy of the patient, and a framecoupled to the preform and adapted to be coupled to a support configuredto support the anatomy of the patient. The apparatus also includes alock mechanism coupled to the frame and configured to couple the frameto the support, and an adjuster mechanism coupled to the frame andconfigured to selectively adjust a distance between the frame and thesupport while the frame is coupled to the support.

Other aspects of the invention include a method of immobilizing ananatomy of a patient for treatment. The method includes forming animmobilization element corresponding to the anatomy of the patient byheating a preform to a forming temperature, positioning the heatedpreform with respect to the anatomy of the patient and a supportsupporting the anatomy of the patient, and activating a lock mechanismto lock the preform with respect to the support and immobilize theanatomy of the patient with respect to the support with theimmobilization element. The method also includes adjusting, while theanatomy of the patient is in place in the immobilization element, adistance between the immobilization element and the support byselectively adjusting at least one adjuster mechanism coupled to atleast one of the preform, the support, and the immobilization element.

Even further aspects of the invention include a system for immobilizingan anatomy of a patient with respect to a patient anatomy support. Thesystem includes an immobilization device, means for locking theimmobilization device with respect to the patient anatomy support, andmeans for adjusting a distance between the immobilization device and thepatient anatomy support while the immobilization device is coupled tothe patient anatomy support.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the following detailed descriptionwhen read in connection with the accompanying drawings, with likeelements having the same reference numerals. When a plurality of similarelements is present, a single reference numeral may be assigned to theplurality of similar elements with a small letter designation referringto specific elements. Included in the drawings are the followingfigures:

FIGS. 1A and 1B are diagrams illustrating an exemplary layout for animmobilization device for use during radiotherapy, neurosurgery or forgeneral cranial immobilization in accordance with aspects of the presentinvention. These diagrams demonstrate an embodiment that is particularlywell suited to neurosurgery as the apex of the head remains uncoveredand accessible;

FIG. 1C is a diagram illustrating the adjustment between an anteriorframe and a posterior support. A posterior element is also interposedbetween the frame and support in accordance with aspects of theinvention.

FIG. 2 is a diagram illustrating an exemplary layout for animmobilization device for use in immobilizing a patient's anatomy inaccordance with aspects of the present invention;

FIGS. 3A , 3B and 3C are diagrams illustrating an exemplary apparatusconfigured for immobilizing a patient in accordance with aspects of thepresent invention;

FIGS. 4A, 4B, 4C, 4D, and 4E are diagrams illustrating an exemplary lockand adjuster mechanism in accordance with aspects of the invention;

FIGS. 5A and 5B are diagrams illustrating an exemplary operation foradjusting a distance of the frame relative to a support for the systemin accordance with aspects of the invention;

FIGS. 6 and 7 are diagrams showing exemplary discrete and continuousadjustments, respectively, according to aspects of the invention;

FIGS. 8 and 9 are diagrams showing alternative locking and adjustmentmechanisms in accordance with aspects of the present invention;

FIG. 10 is a diagram illustrating an exemplary support in accordancewith aspects of the invention;

FIGS. 11A and 11B are diagrams illustrating an exemplary cushionretaining device;

FIG. 12 is a flowchart illustrating the steps of an exemplary method forimmobilizing a patient in accordance with aspects of the invention;

FIG. 13 is a diagram of an immobilization device in accordance withaspects of the invention;

FIG. 14 is a diagram of a support and immobilization device according toaspects of the invention;

FIG. 15 is a diagram of a posterior mask according to aspects of theinvention;

FIG. 16 is a diagram of an anterior mask in accordance with aspects ofthe invention;

FIG. 17 is a diagram of an immobilization element incorporating both theframe and support in a symmetric fashion such that two similar oridentical elements may be interlocked and adjusted with respect to eachother according to aspects of the invention;

FIG. 18 is a diagram of a support or immobilization element inaccordance with aspects of the invention. A frame and support arecoupled to a low melting temperature thermoplastic such that the preformcan be molded, interlocked to itself, and adjusted;

FIG. 19 is a diagram showing a cushion placed in a cushion holderaccording to aspects of the invention;

FIG. 20 depicts a patient immobilization device with adjustmentmechanisms integrated into a support in accordance with aspects of theinvention;

FIG. 21 depicts an adjuster mechanism for adjusting a distance between asupport and an immobilization element in accordance with aspects of theinvention;

FIGS. 22A, 22B, and 22C depict adjustment of an adjustment mechanismaccording to aspects of the invention;

FIG. 23 is a cross-sectional view of an adjustment mechanism inaccordance with aspects of the invention;

FIGS. 24A, 24B, and 24C are diagrams of an adjustment mechanismaccording to aspects of the invention; and

FIGS. 25A and 25B are diagrams of an adjustment mechanism in accordancewith aspects of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the present invention relate generally to apparatus andmethods for immobilizing patients. The apparatus and methods disclosedherein desirably provide adjustable, non-invasive patientimmobilization. As used herein, non-invasive patient immobilizationrefers to immobilization without the need for components that physicallyattach to the patient (e.g., bone screws).

In order to compensate for changes in a patient's anatomy over time,patient thermoplastic immobilization solutions for StereotacticRadioSurgery (SRS) and radiation therapy optionally include a series ofloose and/or separate “shim” components. These shims can be added orsubtracted to either tighten the immobilization system or to loosen it.This is required in order to obtain a high degree of immobilizationwhile maintaining an acceptable level of patient comfort. Patients maygain or lose volume (e.g. fat, water) from the time of simulation to thetime of treatment or subsequent fractions. Such shimming requirementscan result in a large number of components and associated locking clipsto accommodate varied shim thickness. Shims can run from 0 mm to 4 mm in1 mm increments. Also, such shimming requires removing theimmobilization device from the anatomy of the patient and cannot beperformed with the immobilization device in place.

Shimming can be cumbersome and adds a significant amount of time to thepatient setup process. Systems that lack a shimming capability, however,cannot adequately adapt to patient geometry to provide sufficientimmobilization in certain applications. Accordingly, preferredembodiments of this invention can eliminate the use of separate shimcomponents while providing adjustment for improved immobilization. Inaddition, embodiments of this invention permit adjustment withoutremoving the system from the patient.

Embodiments of the present invention are particularly advantageous foruse during stereotactic radiosurgery and radiation therapy, but may alsobe utilized for cancer treatment, radiosurgery, occupational therapy,splinting, plastic surgery, surgery, invasive neurosurgery, etc. Thoseof skill in the art will understand other treatments for which thedisclosed apparatus and methods may be utilized. During stereotacticradiosurgery, a high dose of radiation is delivered precisely to an areaof the patient (such as a region of the patient's head). When a patientis referred for stereotactic radiosurgery they will first undergo aprocess known as simulation. The purpose of this process is to acquirean image (typically a DICOM data set) for planning and treatment withthe patient immobilized in the same devices and position that will beused during treatment and to perform imaging of the patient usingtechniques such as computed tomography (CT), magnetic resonance (MR),positron emission tomography (PET), or a hybrid imaging technique suchas PET/CT or PET/MR. Depending on the case, clinical center, andtechniques being used this simulation step may occur on the same day oftreatment or may occur up to a week or more prior to treatment. In caseswhere an invasive immobilization frame is used, simulation and treatmenttypically occur on the same day in order to minimize stress to thepatient and opportunities for complications. Accordingly, athermoplastic mask may be used to immobilize the patient in accordancewith aspects of the present invention.

This low melting temperature thermoplastic mask, also referred to hereinas a preform, will then be used to immobilize the patient each time thepatient returns for treatment. There are instances in which it isdesirable to adjust the anterior/posterior position of this mask withrespect to the patient. This can occur for a number of reasons includingshrinkage of the thermoplastic mask and weight loss or gain of thepatient. Additionally, the preform may accommodate the use of a biteblock to immobilize the patient's upper palette. Examples of bite blocksare described in PCT Application No. PCT/US14/39764, entitled “HEAD ANDJAW IMMOBILIZATION DEVICE”, the contents of which are incorporated byreference herein. Aspects of the present invention provide for thisadjustment through, in one embodiment, adjustable locking mechanisms(e.g., locking pins). While any number of locking pins can be used, in apreferred embodiment six locking pins are used for each thermoplasticmask. The locking pins can either be permanently or removably attachedto the frame of the mask.

While the present embodiments are described herein with respect tostereotactic radiosurgery, it will be understood that the invention isnot so limited. Aspects of the present invention may be used in anyapplication where patient immobilization is required. Other suitableapplications include immobilizing a patient for neurosurgery (as shownin FIGS. 1A and 1B), immobilizing injured or broken bones of a patient(as shown in FIG. 2), or immobilizing a patient during medical scans orimaging, such as magnetic resonance imaging.

In general, exemplary patient immobilization devices in accordance withaspects of the present invention include a shape corresponding to aportion of the patient's anatomy formed from a low melting temperaturethermoplastic. An immobilization device can optionally include a framecomponent, an integral frame portion, or can be provided without anyframe. In other words, the frame is optionally a portion of theimmobilization device or a preform, or both. The immobilization devicemay be a preform, constructed from a low-melting temperaturethermoplastic, configured to be formed to an anatomy of a patient. Theimmobilization device may also be formed from a rigid, semi-rigid, ornon-rigid material, contoured to an anatomy of a patient.

According to one embodiment, a frame is coupled to the preform tostabilize and support the preform. A lock mechanism (e.g., a lockingmechanism, a lock, etc.) is either permanently or removably coupled tothe frame. The lock is configured to couple the frame to a patientsupport. For example, the frame may be locked to the support, attachedto the support, in place on the support in an unlocked state. Anadjuster mechanism (e.g., an adjustment mechanism, and adjuster, etc.)is coupled to at least one of the frame and the patient support. Theadjuster is configured to provide selective adjustment of the distance(e.g., the vertical height) between the frame and the patient support.

In accordance with other aspects of the invention, exemplary patientimmobilization devices include a cushion retaining device which is usedin conjunction with a formable patient cushion. The cushion retainingdevice provides support for the cushion and hence increases the rigidityand repeatability of the placement of the cushion. This cushionretaining device may be used in conjunction with the preform and framedescribed previously to provide superior patient immobilization.Additional details of aspects of the present invention are providedbelow with reference to the drawings.

FIGS. 3A 3B, and 3C illustrate an exemplary apparatus 100 configured forimmobilizing a patient in accordance with an aspect of the presentinvention. Apparatus 100 may be usable to immobilize a patient during amedical procedure involving the patient's head, such as stereotacticradiosurgery. As a general overview, apparatus 100 includes a preform110, a frame 120, and at least one lock 130. Additional details ofapparatus 100 are described below.

Preform 110 is formed over an anatomy of the patient. The positioning ofpreform 110 may be selected based on the procedure to be performed onthe patient. In an exemplary embodiment, preform 110 is formed to thepatient's head, as illustrated in FIG. 3A. In this embodiment, preform110 may include a plurality of cutouts 114 in order to facilitatecomfort of the patient, as well as allow the user to breath/see throughpreform 110. Preform 110 may also a plurality of perforations 112 inareas that do not affect the ability of preform 110 to immobilize thepatient.

Preform 110 may be formed from a low melting temperature thermoplastic.Suitable thermoplastics include, for example, polycaprolactone (PCL). Tocreate the shape of the patient's anatomy, preform 110 is first heatedto a forming temperature (e.g., a temperature above its meltingtemperature), which causes the preform to enter a state in which it ispliable. Preform 110 may be heated using a number of methods including,for example, a hot water bath or an oven. While the preform is in thisheated state, it is pressed against or around the patient's anatomy(e.g., the patient's head) and allowed to cool. Once cooled, thethermoplastic retains the shape of the patient's anatomy and becomesrigid, thereby preventing or resisting movement of the patient. Thethermoplastic of preform 110 may be of any thickness, the thicknessbeing chosen based on the level of rigidity required for the applicationor procedure. For stereotactic radiosurgery applications, preform 110preferably has a thickness of at least about 3 mm. Filler materials maybe optionally added to the thermoplastic in order to increase thestiffness of the material.

Additional details regarding the features of preform 110, or any otheraspects of the present invention, may be found in U.S. PatentApplication Publication No. 2014/0182603 A1, and in Patent CooperationTreaty Application No. PCT/US2014/039764, the contents of each of whichare incorporated herein by reference.

Frame 120 is coupled to preform 110. Frame 120 provides support forpreform 110 during and following the process of forming preform 110 tothe shape of the patient's anatomy. As shown in FIG. 3A, more than oneframe 120 may be used for a respective preform 110.

Like preform 110, frame 120 is shaped to correspond to the portion ofthe patient's anatomy to be immobilized by apparatus 100. Frame 120 maybe constructed of any material, including a thermoplastic material, solong as the melting temperature of the frame material is higher thanthat of the preform. Thus, frame 120 will retain its rigid shape andsupport preform 110 when preform 110 is deformed to correspond to theshape and contour of the patient's anatomy.

Together, preform 110 and frame(s) 120 form a patient restraint that canbe attached to a patient support 190 in order to immobilize the patient.While one patient restraint is illustrated in FIG. 3A, it will beunderstood that apparatus 100 may employ multiple patient restraints toimmobilize the patient. For example, apparatus 100 may include ananterior patient restraint and a posterior patient restraint sized tomate or attach to one another. The frame 120 is attached to the patientsupport 190 via locks 130 positioned around the frame 110.

Referring to FIGS. 3B and 3C, the frame 120 includes a plurality ofopenings 121. Openings 121 are provided so that frame 120 can be alignedproperly to other structures, such as patient support 190. The patientsupport 190 may include protrusions adapted to fit through the openings121 such that the frame can be positioned on the patient support 190.The frame 120 may also include a series of ports 122 adapted to receivea lock and adjuster 135 (reference numeral 135 as used herein refers tothe lock and adjuster in combination in accordance with someembodiments). In addition to being secured to preform 110, frame 120 mayalso be placed on and secured to a support structure 190 in order toimmobilize the patient relative to the support structure 190, as shownin FIG. 3A. In an exemplary embodiment, frame 120 is secured to preform110 and/or support structure 190 using one or more locks 130, as will bedescribed below. Alternatively, frame 120 may be secured to preform 110or support structure 190 using bolts, screws, pins, or otherconventional securements, which will be known to one of ordinary skillin the art from the description herein.

The lock 130 is movably positioned within an opening 122 of frame 120.The lock 130 may also be co-located with an adjuster so as to form thelock and adjuster 135, permitting adjustment of the distance betweenframe 120 and to support structure 190, and to fix frame 120 in aposition relative to support structure 190. In one example, the adjuster(e.g., adjustment mechanism, variable shim, adjustable shim, etc.) maybe rotated in order to adjust the distance of frame 120. Lock 130 mayalso secure frame 120 to preform 110.

By providing an adjuster coupled to at least one of the frame 120 or thepatient support 190, the number of parts to be handled by the user isdrastically reduced. This leads to improvements in efficiency for thecancer treatment center. This adjuster can take many forms including butnot limited to a stepped slider, a wedge, a wheel, and a cam. Byrotating or sliding these forms of the adjuster, the position of framewith respect to the support surface is changed. The adjuster may bepermanently or removably attached to the frame of the mask or thesupport surface.

For example, a rotatable member may be provided such that one aspect ofthe member is a ramped surface. If this ramped surface is positionedbetween the immobilization member and the surface it is placed, arotation of this member will change the position of the immobilizationmember. This may similarly be performed by a ramped or stepped slidingmember.

In an exemplary embodiment, lock 130 is inseparable from frame 120, suchthat lock 130 cannot be removed from frame 120 without disassembly ofone or both components. Alternatively, lock 130 may be removablyattached to frame 130, e.g., by pulling upward with sufficient force onlock 130. As with the other components of apparatus 100, lock 130 ispreferably constructed from materials that are compatible with theprocedure to be performed on the patient, such as polymers.

FIGS. 4A-4C illustrate an example of a co-located lock and adjuster 135in accordance with aspects of the present invention. As a generaloverview, the co-located lock and adjuster 135 includes a shaft 150, anda plunger 160, and a casing 140. Additional details of the co-locatedlock and adjuster 135 are provided below.

Casing 140 provides a base for the co-located lock and adjuster 135.Casing 140 may attach the lock and adjuster 135 directly to frame 120.As shown in FIGS. 4A and 4B, casing 140 may include a plurality ofprotrusions 142 sized to mate or engage with a port 122 of frame 120 inorder to secure casing 140 (and consequently co-located lock andadjuster 135) to frame 120. Protrusions 142 may create a removable orfixed attachment of casing 140 to frame 120. Alternatively, casing 140may be integrally formed as part of frame 120.

Casing 140 further includes a through-hole 144 for accommodating shaft150 and plunger 160. The interior of through-hole 144 includes threading(not shown) sized and pitched to mate with corresponding threading onshaft 150. In an exemplary embodiment, casing 140 includes a pluralityof numeric indicators 146 on an upper surface thereon, the purpose ofwhich will be described in detail below.

Shaft 150 is sized to be received within the threaded through-hole 144of casing 140. The features of shaft 150 are shown in the exploded viewprovided in FIG. 4C. However, shaft 150 is normally contained withincasing 140, and is not removable therefrom. Shaft 150 includes threading152 sized and pitched to mate with the threading on the interior ofcasing 140. Accordingly, rotation of the bonnet 180 causes rotation ofthe shaft 150 within through-hole 144, which vertically displaces theshaft 150 relative to casing 140 based on the pitch of the engagingthreads.

Shaft 150 includes a through-hole 154 for accommodating plunger 160, asshown in FIG. 4C. Through-hole 154 includes one or more keying features155 on the wall thereof. Keying features 155 mate with correspondingfeatures on plunger 160, thereby coupling rotation of plunger 160 toshaft 150, as will be described below. Shaft 150 further includes one ormore extensions 156 separated by gaps 153 at a lower end thereof.Extensions 156 protrude from a lower end of casing 140 when shaft 150 isreceived within casing 140, as shown in FIGS. 4A and 4B. Shaft 150 mayalso include a flange 158. Like extensions 156, flange 158 is positionedoutside of a lower end of casing 140 when shaft 150 is received withincasing 140. Flange 158 may be sized to bear against a surface of anadjacent structure (such as support structure 190).

Plunger 160 includes a plurality of segments having variable diameters.In an exemplary embodiment, plunger 160 includes a first segment 168having a first diameter and a second segment 170 having a seconddiameter. A tapered portion 172 connects the first and second segments168 and 170. Plunger 160 is sized to be received within the through-hole154 of shaft 150. Plunger 160 includes a knob 162 at an upper endthereof to enable a user of apparatus 100 to easily press or turnlocking pin 130. Plunger 160 further includes a flange 164 at a lowerend thereof. Plunger 160 includes one or more keying features 166, asshown in FIG. 4C, which are sized to mate with keying features 155 onshaft 150.

The locking mechanism (e.g., the lock) is provided by the interactionbetween the flange 164, extensions 156, first segment 168, secondsegment 170, keying features 166, gaps 153 and tapered portion 172. Theadjustment mechanism (e.g., the adjuster) is provided by the interactionbetween the plunger 160, the knob 162, the keying features 166, thethreading 152, the threaded through-hole 144, and the keying features155.

In the first (or unlocked) state, plunger 160 is in an undepressedposition. In this state, segment 168 having the smaller diameter ispositioned radially inward from extensions 156 (or radially inward fromthe projections formed on the inner walls of extensions 156, ifincluded). Segment 168 is sized so that it does not bear againstextensions 156, and as a result, extensions 156 remain in a normal,unforced position (parallel to the axis of plunger 160, as shown inFIGS. 4A and 4B). In this unforced position, extensions 156 do notcontact the inner walls of the mating hole on support structure 190, andshaft 150 is free to move relative to support structure 190 (e.g., byrotation of plunger 160).

In the second (or locked) state, plunger 160 is in a depressed position.During depression of plunger 160, tapered portion 172 is pressed againstextensions 156 until segment 170 having the larger diameter ispositioned radially inward from extensions 156 (or radially inward fromthe projections formed on the inner walls of extensions 156, ifincluded). Segment 170 is sized so that it bears against extensions 156,and as a result, extensions 156 are forced radially outward. In thisforced position, extensions 156 bear against or lock with the innerwalls of the mating hole on support structure 190, and shaft 150 islocked in place relative to support structure 190. It is contemplatedthat the locking mechanisms may be integrated into the support structurerather than the frame of the preform.

The operation of the lock in one example is provided as followed.Extensions 156 are positioned within a mating hole on a structure towhich a frame 120 is to be attached, e.g., in support structure 190.Depressing the plunger 160 moves the flange 164 at the end of the secondsegment 170 downward. The flange 164, second segment 170, taperedportion 172 and first segment 168 extend downward pass the extensions156. The larger diameter of the first segment 168 forces the extensions156 radially outward. The bottom portion of the keying features 166 maythen extend into the gaps 153 between the extensions 156. The contactbetween the first segment 168, the keying features 166, the extensions156 and the gaps 153 provide sufficient force to lock the lock andadjuster 135 with respect to a frame or patient support. To release thelock, the plunger 160 may be returned to its original position, whichremoves the keying features 166 and the first segment 168 from contactwith the extensions 156. The lock optionally may locate the mask withrespect to the support surface or this function may be performed byanother feature such as a pin or boss.

The adjustment mechanism (e.g., adjuster) operates as followed accordingto one example of the invention. The keying features 166 are received bykeying features 155, which causes the shaft 150 to rotate upon rotationof the plunger 160, via the interaction between the threading 152 andthe treaded through-hole 144. Rotation of the plunger 160 (e.g., via theknob 162) adjusts the position of the flange 158 with respect to theother components. Advantageously, the adjustment may be performed withthe co-located lock and adjuster 135 are either in the locked state orin the unlocked state.

In operation, flange 158 contacts a surface of support structure 190surrounding the mating hole in which extensions 156 are positioned.Accordingly, vertical movement of shaft 150 relative to casing 140results in movement of the adjacent surface of support structure 190relative to casing 140. In other words, rotating shaft 150 within casing140 adjusts the vertical distance or spacing of casing 140 (and therebyframe 120) relative to support structure 190 due to the contact betweenflange 158 and the surface of support structure 190.

FIG. 4D is a cross sectional diagram of the co-located mechanism 135 inthe locked position. Depressing the plunger 160 extends it through anopening 149 in the structure 148 (the structure 148 being, for example,a frame, a support, etc.). The first section 170 of diameter larger thanthe second section pushes the extensions 156 radially outward such thatthey extend partially over the edge 147 of the opening 149. Theextension of the extensions 156 creates an interference lock between theelements being locked. In one aspect of the invention, the adjustermechanism advantageously cannot be adjusted when the lock is in thelocked position, such that the distance between the support and theframe cannot be changed. This may be preferred in some applications toprevent inadvertent adjustment of the distance between the support andthe frame. For example, it may be beneficial to avoid inadvertentloosening of the immobilization element from the anatomy of the patientduring treatment. In an embodiment, the radially outward extension ofthe extensions 156 of the mechanism 135 while in a locked positionprevent rotation of the plunger 160 such that the adjustment mechanismmay not be activated.

As described above, the mechanism 135 may also include an indexingmechanism as shown in FIG. 4E. The bonnet 180 has formed in it grooves188 that are configured to receive a protrusion 186 formed at the end ofa flange 184 (e.g., a spring). Rotation of the bonnet 180 may push theprotrusion 186 out of the groove 188 by depressing the flange 184downward. When the bonnet 180 is rotated to another discrete position asis formed by a groove 188, the spring force of the flange 184 pushes theprotrusion 186 into the groove 188, which may cause an audibleindication (e.g., a click noise), that the bonnet 180 has been rotatedto a next discrete position. Other indexing mechanisms may be utilizedas will be understood by those of skill in the art, such as a cam, step,etc.

A change in the distance of frame 120 relative to support structure 190according to the above operation is illustrated in FIGS. 5A and 5B. Asshown in FIG. 5A, frame 120 is coupled to the support structure 190. Inthis state, the adjuster 135 is adjusted to rotate the shaft 150 to beat a vertically upper position within casing 140 (i.e. an “unscrewedposition”). In contrast, as shown in FIG. 5B, a space 192 is createdbetween frame 120 and support structure 190. In this state, the adjuster135 is adjusted to rotate the shaft 150 to be at a vertically lowerposition within casing 140 (e.g., a “screwed in position”), causingflange 158 to push against support structure 190 and force frame 120upward and away from support structure 190.

By the above operation, the precise distance of frame 120 (and thusapparatus 100) from support structure 190 may be adjusted andcontrolled. This distance may be adjusted in predetermined increments(e.g., 1 mm increments) using detents within casing 140, or may beadjusted continuously over a predetermined range. In order toaccommodate the degree of adjustments that may be required for a numberof different patients or medical procedures, it may be desirable thatcasing 140 and shaft 150 enable total adjustment (or vertical distance)of at least 4 mm.

Generally, one advantage conferred by embodiments of this invention isthe ability to adjust the distance between an immobilization device anda patient support while the two are coupled to one another. Suchcoupling may include a locked arrangement, a partially lockedarrangement (for example in a system with multiple locks or adjusterswhen only some but not all of the locks are engaged), an unlockedarrangement, or an arrangement in which the immobilization device is notremoved or separated from the patient support. Accordingly, a couplingbetween the immobilization device and the patient support contemplatesany of these possible arrangements.

Apparatus 100 is not limited to the above components, but may includeadditional or alternative components as would be understood by one ofordinary skill in the art from the description herein.

For one example, a bonnet 180 may be provided for visual indications toa user regarding the spacing of frame 120 (e.g., position of the lockingmechanism) from support structure 190. As explained above, casing 140may include indicators 146 on an upper surface thereof. In thisembodiment, the bonnet 180 may include a window 182 for selectivelyrevealing the indicators to a user of the locking pin 130. Bonnet 180 iscoupled to plunger 160 in order to be rotated. As shown in FIG. 4A,bonnet 180 includes a window 182 to selectively reveal one of theindicators 146 on casing 140 based on the rotated position of bonnet180.

It is preferred but not required that the bonnet 180 (and thereby theshaft 150) rotate to discrete locations around the arc. These discretelocations correspond to predetermined positions that are preferred fortreatment. By rotating to discrete locations it can be assured that asnug, repeatably fitting mask is achieved each time. The position may beadjusted with the mask already in place on the patient or may beadjusted prior to placing the mask on the patient. An indexingmechanism, such as a spring or cam, may be provided to cause therotation of the plunger 160 to be stopped (or triggered) at discretelocations. In an example, the indexing mechanism provides a clickingsound to indicate that a discrete location has been reached by theadjuster.

Advantageously, the adjuster may provide for both discrete andcontinuous adjustment. For example, the indexing mechanism may beconfigured to index rotation at discrete locations, but the adjuster maybe rotated and stopped at positions between or outside the indexeddiscrete locations. For discrete operation, casing 140 and/or shaft 150may include detents to allow adjustment of the distance in predeterminedincrements (e.g., 1 mm). In this embodiment, each detent may beassociated with a particular indicator 146 on casing 140. Accordingly,as the lock and adjuster 135 is adjusted through each increment, window182 of bonnet 180 is configured to reveal the corresponding indicator146 on casing 140. This feature desirably provides a visual indicationto a user of apparatus 100 of the spacing created or maintained at thatlocation. An exemplary operation of an adjuster 181 with bonnet 180through a plurality of numeric increments is shown in FIG. 6.

For continuous operation, casing 140 may include a single, continuouslyvarying indicator 148, as shown in FIG. 7, as opposed to discretenumeric indicators 146. In this embodiment, bonnet 180 may include anarrow or other projection 184 for visually indicating to the user thedegree of spacing using the continuously varying indicator 148.

For another example, apparatus 100 may include separate adjusting andlocking components. While the co-located lock and adjuster 135 isdescribed herein as a single component capable of performing bothadjustment and fixing functions, it will be understood that thosefunctions can be separated. An exemplary embodiment of a frame 120including separate locking and adjusting components is illustrated inFIGS. 8 and 9.

As shown in FIG. 8, frame 120 may include a first set of locks 200 aincluding the plunger/shaft extension interaction of locking mechanismof lock and adjuster 135, and a second set of components 210 (e.g.,adjusters) integrated separately from the locks 200 a in the frame 120.Locking mechanisms 200 a function to lock frame 120 in place by forcingextensions to bear against or lock with a mating hole on an adjacentstructure, as described above. Adjusters 210 function to adjust thespacing between frame 120 and an adjacent structure by allowing a userto turn the exposed knob in discrete or continuous increments.

While locking mechanisms 200 a are illustrated in FIG. 8 as including alocking plunger, it will be understood that other locking mechanisms maybe employed, such as swivel locking mechanisms 200 b, as shown in FIG.9. Advantageously, the locking mechanisms 200 a and the adjusters 210are separately integrated, such that locks 200 are coupled to anotherstructure, such as a patient support. Alternatively, the locks 200 maybe integrated into the frame while the adjusters 210 may be integratedinto another structure, such as a patient support. Other suitablemechanisms for locking frame 120 in a position relative to a supportstructure will be known to one of ordinary skill in the art from thedescription herein. For example, the locking mechanisms can bepositioned on the frames, support structures, etc. and may be integratedseparately from the variable shims, together with the variable shims, ora combination thereof. Furthermore, the adjusters may be integrated inthe frames, support structures, interposed elements, etc. and may beintegrated separately from the locks, together with the locks, or acombination thereof.

In an embodiment of the invention the locks are attached to the frame ofthe thermoplastic immobilization device. In this embodiment a splitframe is shown in which the left and right side of the frame are notconnected other than with the thermoplastic preform. This split frametype allows a mask to be formed while minimizing the amount of stretchto the preform.

In an embodiment, a support structure is provided on which the frame ofthe thermoplastic mask rests when immobilizing a patient. This supportstructure provides the mating holes for the lock to engage. By raisingthis support structure anterior with respect to the patient supportsurface it is possible to increase the resistance of the mask tomovement. This is accomplished because raising this support structurereduces the length of the sidewall of the mask. It also reduces theamount of stretch of the mask required to form the mask around thepatient's anatomy. The height of the support structure can be any heightchosen to optimize the rigidity of the mask while maintaining clearancefor desired treatment beam paths. Preferably, this height isapproximately 8 cm above the patient support surface. The supportstructure also provides locating pins which position the immobilizationmember with respect to the support structure. These are in addition tothe locking pins. These locating pins provide a tightly tolerancelocational accuracy which ensures the repeatability of placement of theimmobilization members.

For still another example, apparatus 100 may include a patient support220. An exemplary patient support 220 is illustrated in FIG. 10. Patientsupport surface 220 is a large, flat surface on which the patient can bepositioned during the medical procedure. Suitable patient supportsinclude beds, tables, gurneys, or other well-known surfaces on which aseated or supine patient can be positioned. Support structure 190 may beintegrally formed with support surface 220, or may be a separatestructure 190 that is placed on and movably positioned with respect tosupport surface 220. When support structure 190 is separate from patientsupport surface 220, it may be desirable that support structure 190 beremovably attached to surface 220 to enable consistent, repeatablepositioning of support structure 190. Suitable components for removablyattaching support structure 190 to surface 220 will be known to one ofordinary skill in the art from the description herein.

Support structure 190 is positioned on patient support 220 such that atop surface 194 thereof is positioned anterior to patient supportsurface 220. In an exemplary embodiment, the top surface 194 of supportstructure 190 is spaced a predetermined distance (e.g., approximately 10cm) from patient support surface 220.

In addition to the support surface and immobilizations element,additional elements may be interposed between the support surface andthe frame of the immobilization element. These can include items such asadditional preforms, cushions, cushion retaining devices or anyalternative elements understood by one of ordinary skill in the art fromthe description herein. Cushions and cushion retaining devices are shownas examples in FIGS. 11A, 11B and 19. An interposed posterior maskpreform is shown as examples in FIG. 15 in its unformed condition. Item18 in FIG. 1B and item 502 in FIG. 14 show examples of interposedposterior masks in their formed state. Adjustment mechanisms may beoptionally coupled to one or more interposed elements.

In addition to support structure 190, apparatus 100 may include acushion retaining device 230 for retaining a formable cushion. Anexemplary cushion retaining device 230 is illustrated in FIGS. 11A and11B. The formable cushion is used to support the portion of the user'sanatomy in a stable, immobile position. Additional details regardingformable cushions for use with the present invention, or any otheraspects of the present invention, may be found in Patent CooperationTreaty Application No. PCT/US2014/050335, the contents of which areincorporated herein by reference.

In order for the formable cushion to be capable of repeatably andreliably retaining the patient's anatomy (e.g. the patient's head) in astable, immobile position, cushion retaining device 230 is configured tosupport the formable cushion. In an exemplary embodiment, cushionretaining device 230 supports the formable cushion on the posteriorsurface of the cushion. As shown in FIG. 19, where formable cushion isshaped to cushion a patient's head, cushion retaining device 230 iscontoured to support the posterior surface of the cushion, as well asthe sides of the cushion around the top and sides of the user's head.This support assists in reliably and repeatably immobilizing the user'shead during repeated medical procedures.

Cushion retaining device 230 is desirably formed from a rigid materialto prevent deformation or movement of the formable cushion. Suitablematerials for cushion retaining device 230 include, by way of example,fiber reinforced composites or plastics. Like the other components ofapparatus 100, cushion retaining device 230 is preferably constructedfrom materials that are compatible with the procedure to be performed onthe patient. Cushion retaining device 230 preferably has a thickness ofno more than 2 mm.

As shown in FIG. 11A, cushion retaining device 230 is desirably indexedto support structure 190, so that the position of cushion retainingdevice 230 relative to support structure 190 can be tracked andrepeated. To make repeated immobilization of the patient possible, thepreform of apparatus 100 (not shown in FIG. 11A) may also be indexed tosupport structure 190, so that the elements on both sides of thepatient's head are tracked with respect to an immobile object (i.e.support structure 190).

This cushion retaining device supports the cushion. The cushionretaining device is preferably contoured to provide a comfortableposition for the patient. The cushion retaining device is preferablyconstructed of a stiff material to provide the maximum amount of supportto the cushion. Examples of materials to be used include fiberreinforced composites, or any other material suitable for theapplication. The cushion retaining device is preferably thin to minimizeits effect on the treatment beam. A preferred thickness is approximately2 mm. This retaining device may be constructed of MR compatiblematerials to allow the device to be used for MR imaging.

In one embodiment the cushion retaining device is indexed to the samesupport structure as the anterior thermoplastic immobilization device asshown in FIG. 11A. This may be the surface that the patient is lying onor may be a secondary support structure. By indexing both immobilizationdevices to the same surface increased repeatability of positioning isachieved. This indexing may be accomplished by the locking pins or maybe accomplished through another feature including but not limited to:pins, bosses, and recesses.

FIG. 12 is a flowchart illustrating an exemplary method 300 forimmobilizing a patient in accordance with an aspect of the presentinvention. The steps of the method 300 of immobilizing an anatomy of apatient for treatment, including step 302 of forming an immobilizationelement corresponding to the anatomy of the patient. The forming step302 includes step 302 a of heating a preform to a forming temperature,step 302 b of positioning the heated preform with respect to the anatomyof the patient and a support supporting the anatomy of the patient, andstep 302 c of activating a lock mechanism to lock the preform withrespect to the support and immobilize the anatomy of the patient withrespect to the support with the immobilization element. The method 300also includes step 304 of adjusting, while the anatomy of the patient isin place in the immobilization element, a distance between theimmobilization element and the support by selectively adjusting at leastone adjuster mechanism coupled to at least one of the preform, thesupport, and the immobilization element.

In step 302, an immobilization element is formed over an anatomy of apatient. The immobilization element may be a preform formed of lowmelting temperature thermoplastic. At step 302 a, the immobilizationelement may be formed by heating a preform to a forming temperature.This allows the immobilization element to be formed and contour to theanatomy of the patient.

In sub step 302 b, the heated preform is positioned with respect to theanatomy of the patient. In one embodiment, the heated preform may beassociated with a frame to create the immobilization device. The framemay be similar to the frames described above. In an embodiment, theframe may be positioned over a support, such that the support includescorresponding indexes to permit positioning of the frame. In anotherembodiment, the frame is positioned with another frame. For example, asecond frame may include a support constructed of low temperaturethermoplastic that supports an anatomy of a patient, and positioning thefirst frame over the second frame constructs a splint with the supportand the immobilization element. The frame may also be positioned withitself in embodiments where the top of the frame is constructed to meetcorresponding indexes on the bottom of the frame. For example, theimmobilization element may be configured to wrap around the anatomy ofthe patient until one side of the frame meets with another side of theframe, as shown for example in FIG. 18.

In step 302 c, a lock mechanism is activated to lock the preform to asupport. The lock mechanism may be the locks such as those describedabove. The lock mechanism may be an interference lock configured tocreate an interference between the lock and the frame and/or supportwhen the lock mechanism is activated. Locking the preform allows thepreform to form into an immobilization element when the preform cools toroom temperature.

In step 304, the distance between the immobilization element and thesupport is adjusted with an adjuster mechanism. The adjuster mechanismmay be similar to the adjuster and adjustment mechanism as describedabove. The distance between the immobilization element and the supportis adjusted to ensure a tight and accurate fit between theimmobilization element, support, and anatomy of the patient.Advantageously, the adjusters disclosed herein permit adjustment of thedistance between the immobilization and the support while the anatomy ofthe patient is immobilized and without removing the anatomy from theimmobilization element, the immobilization element from the support,etc. Additionally, the distance between the immobilization element andthe support may be adjusted without locking the immobilization elementto the support (e.g., in an unlocked position). This allows for highlyaccurate, easily repeatable immobilization without the use of cumbersomeparts and without interrupting the immobilization of the anatomy of thepatient.

Method 300 is not limited to the above steps, but may include additionalor alternative steps as would be understood by one of ordinary skill inthe art from the description herein.

For one example, method 300 may include steps of treating the patientafter the distance between the frame and the support are adjusted withthe adjuster mechanism. The treatment may include stereotacticradiosurgery, radiosurgery, radiation treatment, cancer treatment, etc.The above list of treatments is exemplary and not exclusive. Those ofskill in the art will understand various treatments that will benefitfrom and can utilize the disclosed systems, apparatus, and methodsherein.

Referring back to FIGS. 1A and 1B, the preform 10 is formed over thehead 15 of the patient 12. The frame 13 is split into two sides, andeach side is provided with locking mechanisms 14 such as those describedabove. In such embodiments, the preform 10 is formed such that a portionof the head 15 of the patient 12 is left open. These applications may beadvantageously utilized in neurosurgery applications. Typicalneurosurgery requires the head of the patient to be immobilized, andusual immobilization is performed by inserting screws or other fasteningdevices directly into the head of the patient. The preform 10 depictedin FIGS. 1A and 1B permits immobilization of the patient head whileproviding access to the patient's head to a neurosurgeon. Thus, thepatient 12 can be immobilized non-evasively.

In FIG. 1A, the head 15 of the patient rests in a cushion 16 that isplaced in a support structure 17. In FIG. 1B, the head 15 of the patient12 rests on a posterior preform 18 that is connected to the support 17.The posterior preform 18 may be constructed of a low melting temperaturethermoplastic and formed to conform to the back of the head 15 of thepatient 12. FIG. 1C depicts the adjustment of the distance between theframe 11 and 13 and the support 17. In FIG. 1C, the head 15 of thepatient is shown resting on a posterior preform 18, although the head 15may be resting on a cushion 16 as shown in FIG. 1A or both a cushion 16and posterior preform 18. Adjustment of the adjuster mechanisms canselectively decrease the distance between the frames and support asindicated by the arrows, and selectively increase the distance betweenthe frames and the support.

Referring to FIG. 2 again, a splint 20 is depicted. The splint 20includes a support 23 and an immobilization element 22 that are formedover the arm 21 of a patient. The support 23 and immobilization element22 may be rigid and/or constructed of a formable thermoplastic such thatthe support 23 and immobilization element 22 are contoured to theanatomy of the patient. As depicted, the immobilization element 22includes a frame 24 that has co-located lock and adjuster mechanisms 26integrated into the frame 24. The support 23 also includes a frame 25that is adapted to attach to the frame 24 via the mechanisms 26.Alternatively, the mechanisms 26 may be positioned on the frame 25 ofthe support 23 or a combination of mechanisms 26 may be positioned onboth the frame 24 of the immobilization element 22 and the frame 25 ofthe support 23.

With reference to FIG. 13, a patient immobilization device 400 is shown.The immobilization device 400 may be constructed of materials similar tothe immobilization devices (e.g., preforms) as described above. Thepatient immobilization device 400 is adapted to be positioned and formedover the head, shoulders, and chest of a patient. Advantageously, theimmobilization device 400, by being positioned over the chest andshoulders of the patient, can be used to immobilize the shoulders andchest of the patient for particular treatments, such as lymph nodecancer treatment. The immobilization device 400 may reduce the movementof the tumor during treatment of the patient. The immobilization device400 additionally includes locking mechanisms (depicted as co-locatedlock and adjuster mechanisms 402) positioned along the frame 404 of theimmobilization device 400.

In the embodiments that utilize multiple lock and adjuster mechanisms,such as the embodiment illustrated in FIG. 13, the lock and adjustermechanisms can be operated independently to lock, unlock, or adjustportions of the immobilization device as needed. For example, it ispossible to use one or more selected adjuster mechanisms to tighten orloosen the fit of the immobilization device with respect to variousportions of the patient's anatomy. This permits localized adjustment ofthe immobilization device. For example, in an application in which thehead of a patient is immobilized for treatment, it may be advantageousto adjust the fit of the immobilization device with respect to thepatient's chin, forehead, or other portion of the patient's head withoutadjusting other portions of the patient's head.

Referring to FIG. 14, in addition to the thermoplastic mask 500described above which is placed on the anterior side of the patient, anadditional thermoplastic preform 502 may be used and formed to theposterior side of the patient's anatomy. By providing these twothermoplastic immobilization devices the patient is constrained on allsides of their head. This may provide superior immobilization ascompared to using only a single thermoplastic immobilization device. Inthis embodiment when the locking mechanisms of the anteriorimmobilization device are moved to their second configuration (engagingmating holes on the support) they fix both the anterior and posteriorimmobilization devices in place. When the adjuster mechanism is rotated(or adjusted in embodiments where the adjuster is adjusted by othermethods) it increases or decreases the distance between the frame of theanterior and posterior immobilization devices.

FIGS. 15 and 16 depict a posterior preform mask 600 and anterior preformmask 602 that may be used in conjunction with the structure depicted inFIG. 14 in their unformed states. In the embodiments depicted in FIGS.15 and 16, co-located mechanism 616 are positioned on the frame 614 ofthe anterior mask 602. The posterior preform 600 includes athermoplastic mask 604, a frame 606, openings 608 and channels 610. Theanterior preform 602 includes a perforated thermoplastic mask 612(although the mask 612 may not be perforated), a frame 614 that includesa left section 615 and a right section 617, a series of co-locatedmechanisms 616 and channels 618. The openings 608 on the posteriorpreform 600 are configured to lock with the locking mechanisms 616 ofthe anterior preform 602. The channels 610 and 618 are configured toreceive securing pins (not shown) from a support structure to align andsecure the preforms to the structure.

FIGS. 17 and 18 depict examples of immobilization systems 650 and 670.The system 650 includes a support 654 for supporting an anatomy of apatient, and an immobilization element 652. The immobilization element652 has a first side frame 660 with a locking and adjusting mechanism656 and a second side frame 662 with an opening 653. The support 654includes a first side frame 664 with an opening 663 and a second sideframe 665 with a locking and adjusting mechanism 658. The opening 663 isconfigured to receive the mechanism 656 and the opening 653 isconfigured to receive the mechanism 658 such that the mechanisms 656 and658 are of opposite vertical arrangement. It is to be understood thatthe symmetry of this system allows either item 652 or item 654 to beconsidered the immobilization element and the other to be the support.

The system 670 includes an immobilization element 672 (e.g., a preform,a support, etc.), a locking and adjusting mechanism 674, a top frame 676and a bottom frame 678. The immobilization element 672 may be formed toan anatomy of a patient such that the top frame 676 meets with thebottom frame 678, thereby aligning the locking and adjusting mechanism674 with an opening 679 on the bottom frame 678. Thus, a single lockingand adjusting mechanism (or a series of locking and adjusting mechanismsaligned on one side) may be utilized to lock the immobilization element672 to itself and adjust the distance between the top frame 676 andbottom frame 678.

It is another object of this invention to provide an alternative to thissecond thermoplastic immobilization device located posterior to thepatient. In another embodiment a formable patient cushion is used toimmobilize the back of the patient's head.

FIG. 19 depicts another immobilization device in accordance with aspectsof the invention. The device 700 includes a frame 704, and a formablecushion 702 within the device 700. The frame 704 of the device 700includes a plurality of openings 706 that are configured to receivelocking mechanisms and adjustable shims such as those described above.The plurality of openings 706 include a slit 708 that opens through theoutside of the frame 704 to aid in manufacture.

FIGS. 20-23 depict another system with a lock mechanism and adjustermechanism that permits adjustment of an immobilization device whileimmobilizing a patient according to aspects of the invention. Theimmobilization device 800 includes a support 802 that is capable ofsupporting the head of the patient (at the head portion 804) andshoulders of the patient. Positioned along the outer perimeter of thesupport 802 are a plurality of adjuster mechanisms 805 that areintegrated into the support 802. The adjusters 805 take the form of awheel 806 accessible from the outer perimeter of the support 802 andchannels 808 within holes 809 formed in the support 802.

The wheels 806 may be rotated to adjust the distance between animmobilization device (such as a frame and preform) (and thereby apatient immobilization device, such as a frame with a preform) withrespect to the support 802. As shown in FIGS. 22A, 22B, and 22C, thechannel 808 is adapted to receive a lock mechanism 816. As depicted, theimmobilization element 815 is positioned above the support 802, andincludes extensions 820 formed on the underside of the element 815. Theimmobilization element 815 includes openings 818 through which a lockmechanism 816 may be inserted. The channel 808 includes a hole 809 thatis adapted to receive the extensions 820 and the lock mechanism 816. Theouter perimeter of the channel 808 has formed on it a thread 824,although the channel 808 may also or in the alternative have formed onit a cam surface to facilitation rotation and vertical displacement ofthe channel.

The hole 809 of the channel has an upper portion 828 and a lower portion826 of larger diameter, and the upper portion 828 and lower portion 826are separated by an edge 830. The extensions 820 are inserted into thehole 809 such that they extend past the edge 830 and into the lowerportion 826. When the lock mechanism 816 is inserted into the hole 809and through the middle of the extensions 820, the diameter of the lockmechanism 816 causes the extensions 820 to push radially outward, suchthat they bear against the inner wall of the hole 809 and the edge 830.By extending radially outward, the extensions 820 form an interferencelock between the immobilization element 815 and the support 802.

When locked (and also when unlocked), the upper surface 811 of thechannel 808 bears against the lower surface of the immobilizationelement 815. The distance between the immobilization element 815 and thesupport 802 may be adjusted by the adjuster mechanism provided by thewheel 806. Referring to FIG. 23, the wheel 806 includes a matchingformation along the center to match the threading or cam surface 824 ofthe channel 808. A cam surface with a bearing surface may be configuredto increase the distance between the immobilization element and thesupport upon relative movement of the cam surface with respect to theimmobilization element or the support. The rotation of the wheel 806moves the channel 808 vertically. The top surface 811 of the channel 808that is engaged with the lower surface of the immobilization device 815such that movement of the wheel 806 adjusts the vertical position of thechannel 808, thereby adjusting the distance between the surface 802 andthe immobilization element 815, The wheel 806 may also includeindicators (e.g., numbers) on the surface to indicate to the user of thesystem as to the vertical position of the channel 808, and may alsoinclude indexing mechanisms such as those described above.Advantageously, the adjustment of the distance between the support 802and the immobilization element 815 may be performed while the anatomy ofa patient is immobilized and while the immobilization element 815 isstill attached to the support 802.

The embodiments depicted in FIGS. 22A-22C may advantageously permitadjustment of the distance between the immobilization device and thesupport while the immobilization device and the support are unlocked orlocked with respect to one another, in contrast to one embodimentdescribed previously with reference to FIG. 4D. By providing adjustmentwhile the support and immobilization are optionally locked or unlocked,the amount of time required to adjust the system to the desired levelcan be reduced because the time necessary to unlock and relock iseliminated.

Alternative adjustment mechanisms may be utilized in accordance withaspects of the invention. An example of such a system is depicted inFIGS. 24A-24C. The system 900 includes a support 902, a channel 904 witha bottom portion 905 of larger diameter, and a notched column 906 formedin the support 902. The notches 908 are adapted to receive the bottomportion 905 of the channel 904, such that the vertical position of thechannel 904 with respect to the surface 902 may be selectively adjustedby insertion of the bottom portion 905 into differently positionednotches 908 in the notched column 906.

FIGS. 25A and 25B depict another example of an adjuster mechanismaccording to aspects of the invention. The system 1000 includes asupport 1002, a channel 1004 with an opening 1005 and peg hole 1008. Anopening 1006 is formed in the support 1002 and corresponding peg holes1012 are formed on the outer perimeter of the support 1000 at thelocation of the opening 1006. The position of the channel 1004 may beadjusted by insertion of a peg 1010 into the peg hole 1008 through a peghole 1012 formed on the outer perimeter of the support 1002.

In an additional embodiment, the lock mechanism and/or the adjustermechanism can be coupled directly to the preform. For example, the lockmechanism or adjuster mechanism may be pre-assembled to the preform, orassembled at the time of forming the preform to an anatomy of a patient.

Although the invention is illustrated and described herein withreference to specific embodiments, the invention is not intended to belimited to the details shown. Rather, various modifications may be madein the details within the scope and range of equivalents of the claimsand without departing from the invention.

What is claimed:
 1. An adjustable lock configured to retain animmobilization device in position relative to an anatomy of a patientand a patient anatomy support, the adjustable lock comprising: means forlocking the immobilization device with respect to the patient anatomysupport; and means for adjusting a distance between the immobilizationdevice and the patient anatomy support while the immobilization deviceis coupled to the patient anatomy support by the locking means.
 2. Theadjustable lock of claim 1, wherein the locking means comprises a lockcoupleable to at least one of the immobilization device and the patientanatomy support and configured to attach the immobilization device tothe patient anatomy support.
 3. The adjustable lock of claim 2, whereinthe lock includes a plunger movable along an axis between locked andunlocked positions and at least one extension movable radially withrespect to the axis when the plunger is in the locked position.
 4. Theadjustable lock of claim 3, wherein the plunger has a radially extendingportion positioned to push the at least one extension radially outwardwhen the plunger is in the locked position.
 5. The adjustable lock ofclaim 4, wherein the plunger has a tapered portion adjacent the radiallyextending portion.
 6. The adjustable lock of claim 3, wherein the atleast one extension is defined on a shaft within which the plunger canextend.
 7. The adjustable lock of claim 6, the lock further comprising abase defining a through-hole for accommodating the shaft and the plungerand configured for coupling the lock to at least one of theimmobilization device and the patient anatomy support.
 8. The adjustablelock of claim 6, wherein at least one of the plunger and the shaft arekeyed to limit rotation of the plunger relative to the shaft.
 9. Theadjustable lock of claim 1, wherein the adjusting means comprises anadjuster coupleable to at least one of the immobilization device and thepatient anatomy support and configured to selectively adjust thedistance between the immobilization device and the patient anatomysupport while the immobilization device is coupled to the patientanatomy support.
 10. The adjustable lock of claim 9, wherein theadjuster includes a cam surface and a bearing surface, wherein thebearing surface is configured to change the distance between theimmobilization device and the patient anatomy support upon relativemovement of the cam surface with respect to the immobilization device orthe patient anatomy support.
 11. The adjustable lock of claim 10,wherein the adjuster includes a thread providing the cam surface. 12.The adjustable lock of claim 11, wherein the thread of the adjuster ispositioned to be engaged by a surface of at least one of theimmobilization device, the patient anatomy support, and an elementinterposed between the immobilization device and the patient anatomysupport.
 13. The adjustable lock of claim 10, the adjuster furthercomprising a rotator positioned to contact the cam surface and thebearing surface, wherein rotation of the rotator about an axistranslates the cam surface or the bearing surface along the axis andadjusts the distance between the immobilization device and the patientanatomy support.
 14. The adjustable lock of claim 13, the adjusterincluding an indexing mechanism defining discrete positions, eachposition corresponding to a relative distance between the immobilizationdevice and the patient anatomy support.
 15. The adjustable lock of claim14, wherein the indexing mechanism includes a detent positioned toindicate when the rotator is aligned with one of the discrete positions.16. The adjustable lock of claim 14, wherein the indexing mechanismincludes an indicator positioned to provide a visual indication of therelative distance between the immobilization device and the patientanatomy support.
 17. The adjustable lock of claim 1, wherein the meansfor adjusting is configured to selectively adjust the distance betweenthe immobilization device and the patient anatomy support after theimmobilization device is coupled to the patient anatomy support by themeans for locking and while the immobilization device remains coupled tothe patient anatomy support by the means for locking.
 18. A system forimmobilizing an anatomy of a patient with respect to a patient anatomysupport, the system comprising: the adjustable lock of claim 1; and animmobilization device; wherein the adjustable lock is coupled to theimmobilization device and is configured to retain the immobilizationdevice in position relative to the an anatomy of the patient and thepatient anatomy support.
 19. The system of claim 18, wherein the patientanatomy support is a portion of the immobilization device.
 20. Thesystem of claim 18, wherein the patient anatomy support is anotherimmobilization device.
 21. The system of claim 18, wherein theimmobilization device includes a frame and a preform coupled to theframe, the preform being formed from a low melting temperaturethermoplastic and configured to be formed to the anatomy of the patient,wherein the adjustable lock is coupled to the frame of theimmobilization device.
 22. The system of claim 18 comprising pluraladjustable locks coupled to the immobilization device and spaced fromone another, wherein the means for adjusting the distance between theimmobilization device and the patient anatomy support of each of theadjustable locks provides adjustability independent of other ones of theadjustable locks, thereby facilitating adjustment of the fit of theimmobilization device with respect to one portion of the anatomy of thepatient independently from adjusting the fit of other portions of theanatomy of the patient.
 23. The adjustable lock of claim 1, wherein themeans for locking the immobilization device with respect to the patientanatomy support is actuated along an actuation axis and the means foradjusting the distance between the immobilization device and the patientanatomy support is actuated about a rotation axis that corresponds tothe actuation axis.
 24. A method for retaining an immobilization devicein position relative to an anatomy of a patient and a patient anatomysupport, the method comprising: coupling the immobilization device withrespect to the patient anatomy support; and adjusting a distance betweenthe immobilization device and the patient anatomy support while theimmobilization device is coupled to the patient anatomy support.
 25. Themethod of claim 24, wherein the coupling step comprises actuating a lockalong an actuation axis.
 26. The method of claim 25, wherein theadjusting step comprises rotating an adjuster about the actuation axis.27. The method of claim 24, wherein the coupling step comprisesactuating plural locks spaced from one another.
 28. The method of claim27, wherein the adjusting step comprises rotating plural adjustersindependently thereby facilitating adjustment of the fit of theimmobilization device with respect to one portion of the anatomy of thepatient independently from adjusting the fit of other portions of theanatomy of the patient.
 29. An adjustable lock configured to retain animmobilization device in position relative to an anatomy of a patientand a patient anatomy support, the adjustable lock comprising: a lockcoupleable to at least one of the immobilization device and the patientanatomy support and configured to attach the immobilization device tothe patient anatomy support, the lock including a plunger movable alongan axis between locked and unlocked positions and at least one extensionmovable radially with respect to the axis when the plunger is in thelocked position; and an adjuster coupleable to at least one of theimmobilization device and the patient anatomy support and configured toselectively adjust a distance between the immobilization device and thepatient anatomy support while the immobilization device is coupled tothe patient anatomy support, the adjuster mechanism including a camsurface and a bearing surface, wherein the bearing surface is configuredto change the distance between the immobilization device and the patientanatomy support upon relative movement of the cam surface with respectto the immobilization device or the patient anatomy support.
 30. Theadjustable lock of claim 29, the adjuster further comprising a rotatorpositioned to contact the cam surface and the bearing surface, whereinrotation of the rotator about the axis translates the cam surface or thebearing surface along the axis and adjusts the distance between theimmobilization device and the patient anatomy support.